Closure for exhaust pipe for gas engines



May 5, 1953. c. H. HARMON CLOSURE FOR EXHAUST PIPE FOR GAS ENGINESFiled. Jan. 14;, 1950 'IIIII-IIIII'IIIIIIIIII; M,

. INVENTOR. Cline Haf y Hzrmon fim/v 9 5 Patented May 5, 1953 UNITEDSTATES PATENT CLOSURE FOR EXHAUST PIPE FOR GAS ENGINES Cline HarryHarmon, Waterloo, Iowa, assignor to Waterloo Foundry Company, Waterloo,Iowa, a

copartnership Application January 14, 1950, Serial No. 138,650

7 Claims.

The present invention relates to a closure device for protecting theopen end of an upright terminal portion of an exhaust pipe of gasolineand diesel engines and the like. Devices of this general type serve toexclude rain, snow, dust, dirt and foreign matter from entering theexhaust pipe when the engine is not operating, and automatically exposesthe end of said pipe when exhaust gases are discharged therethrough.

More specifically the present invention is directed to improvements inclosure devices in which such device includes a frame member in the formof a ring provided with a laterally extending lug to which acounter-weighted closure flap is pivotally connected.

Preferably, such devices should be constructed and arranged so that theclosure flap is free to move about its pivotal connection in response tothe presence or absence of pressure of the exhaust gases in the exhaustpipe. It is recognized that devices of this general type, by reason oftheir position of use, are subject to relatively high temperatures byreason of the exhaust gases passing through the exhaust pipe, and hencethe metal parts of the closure device are subject to substantialexpansion and contraction over a period of time. By reason of such acondition, it sometimes happens that the pivotal connection of theclosure flap becomes impaired to the extent that the closure fiap doesnot readily move in response to the presence or absence of pressure ofexhaust gases and thus fails to perform its intended function.

The main object of the present invention is to provide a novel form ofpivotal connection or mounting for the closure flap which will insuresatisfactory operation of the closure flap for long periods of time.

- Another object is the provision of an improved pivotal mounting for aclosure device of the character indicated having means for adjustment tocompensate for wear of the moving parts.

Still another object is the provision of an improved pivotal mountingfor a closure device of the character indicated which includes ahardened steel pin rockably mounted in a brass bushing and in which theclosure flap is mounted on said hardened steel pin and includes take-upbushings for engagement with the brass bushing to compensate for wear.

A further object is the provision of an improved pivotal mounting for aclosure device of the character indicated in which a closure flap ispivoted on a laterally extending lug on the frame member and the closureflap has a counter-weight in which is provided a cavity for receivingthe'lug and the side walls of the cavity are provided with means forengaging the lug for spacing the side walls from the lug and therebypositioning the closure flap with respect to the frame.

A still further object is the provision of an improved closure device ofthe character indicated having a frame for mounting on an exhaust pipeand a closure flap pivotally mounted on the frame in which the frame andthe closure flap are provided with large area, interengageable contactsurfaces which serve to limit the movement of the closure fiap to openposition, and because of the large area of the contact surfaces thedanger of damage to either of the two elements making up the device isreduced to a minimum.

With these and other objects in view, my invention consists in theconstruction, arrangement, and combination of the various parts of mydevice whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in my claims, and illustrated in theaccompanying drawings, wherein:

Figure 1 is a plan view of a closure device embodying the presentinvention;

Figure 2 is a reduced scale side elevational view of the device mountedon an exhaust pipe showing a portion of the closure flap in section;

Figure 3 is a reduced scale vertical sectional view of the closuredevice and the exhaust pipe;

Figure 4 is a large scale sectional View taken on line 44 of Figure 2;

Figure 5 is a view taken on line 5-5 of Figure 3; and

Figure 6 is a view similar to Figure 4, illustrating a modified form ofpivot pin.

The closure device comprises a frame It), in the form of a split ring,adapted to surround the upper end of an exhaust pipe as indicated at i2,as clearly seen in Figures 2 and 3 of the drawing. The split ringincludes a pair of laterally projecting, transversely spaced apart earsM adapted to be connected together by a bolt 16, the bolt serving todraw the ears together for firmly clamping the ring around the exhaustpipe.

Extending laterally from the frame or ring H3, at substantiallydiametrically opposite relation to the ears It, is a lug it, to which aclosure flap 2k] is pivotally connected. lhe closure flap is generallyof circular contour, and provided with a marginal depending flange 22,adapted to surround the upper portion of the exhaust pipe 12, and seatsupon the upper end of the split ring Ill. As may be seen in the drawing,the split ring is mounted on the exhaust pipe so that the upper end ofthe pipe projects slightly above the upper surface of the ring and insuch relation that the closure flap will at no time engage the upper endof said pipe.

Formed integrally with the closure flap is a rearwardly extending tailportion 2 1, constituting av counter-weight, the undersurface of whichis recessed, as indicated at 2B, for accommodating therein the mountinglug l8 of the split ring, as clearly seen in Figures 2 and 3 of thedrawing. The side walls 28 of said tail portion, constituting the sidewalls of said cavity 26, are spaced apart a proper distance so as toprovide adequate clearance for the lug l8, as may be seen in Fig. ures1, 4 and 5 of the drawing.

The cavity 26 is defined at its rear extremity by a sloping wall surface36 which is adapted to engage a surface 32 on the lower side of the lug[8. The surface 32 extends the full width of the lug, and extends in theopposite direction a substantially equal distance; the surface 34 of thecavity 26 has at least as great, and slightly greater, dimensions as thecorresponding dimensions of the surface 32. When the closure flap isopened to the position illustrated in Figure 3 the surfaces 30 and 32contact each other, establishing a stop for limiting the openingmovement of the closure flap. When the two surfaces are in engagement,the contact therebetween is distributed substantially throughout thearea of their surfaces. The respective dimensions of the surfaces areclearly illustrated in Figures 3 and 5.

The pivotal connection forming a part of the present invention includesa bushing 34 preferably formed of brass, which is press-fitted in atransverse aperture 36 in the lug it. The bushing 34 may also be formedof other non-ferrous material. The bushing 36 is fitted in the apertureso as to be secured against rotation therein.

Rockably mounted in the bushing 34 is a hardened steel pin 38, the endsof which extend through threaded apertures 4i! in the side walls 28 ofthe tail portion of the closure flap. The pin 38 is snugly fitted in thebushing 34 but is permitted to rock therein.

Surrounding the outer ends of the hardened steel pin 38 are take-upbushings 42 which are slid over the ends of the pin, the bushings beingexteriorly threaded for screwing into the apertures 40. The bushings 42are screwed into position where they engage the ends of bushing 34 tosuch a tightness as to provide a relatively snug fit but permittingrocking of the pin and the take-up bushings 42 with respect to thebushing 34. Outwardly of the take-up bushings 42 (in one form of theinvention, a illustrated in Figure 4) lock washers 44 and lock nuts 46are threaded on the outer threaded extremities of the pin 68. The locknuts 46 and lock washers 44 are turned up tight, locking the take-upbushings 42 in the adjusted positions. The take-up bushings 42 space theside walls 28 with respect to the lug I8 and center said lug betweensaid side walls so as to position the closure flap substantiallycentrally with respect to the frame [0.

In'Figure 6, a pin 38' is employed, but instead of having both endsthreaded, as described in connection with Figure 4, one end is providedwith a bolt head 48, and the other end with a lock washer 44 and locknut 46. The bolt head 48 directly engages the adjacent take-up bushing42. As the closure flap swings open and closed, there is a tendency toconsiderable wear on the pivot connection. As above explained, theclosure flap is forced open by the exhaust gases and because of therepeated impulses of the exhaust gases due to individual explosions ofthe engine, the closure flap actually flutters, that is, it swings orvibrates at a rapid speed and the tendency to wear on the pivotalconnection due to friction is great. The fact that the pin 38 is ofhardened steel and the bushing 34 is of brass, or other nonierrousmaterial, minimizes the wear due to friction. The construction of thepresent invention provides unusual strength and durability.

It is desirable to compensate for what wear that does occur, and thismay be done by adjusting the take-up bushings 42 by turning them intonew positions with respect to the ends of the bushing 34, and thereafterturning up the lock nuts 46 (Figure 4) to lock the take-up bushings intheir new adjusted positions.

In the case of the construction of Figure 6, take-up for wear isaccomplished by adjusting the take-up bushings 42 to the desired newposition, and thereafter tightening the single nut 46. The constructionof Figure 6 constitutes a simple and expedient means for compensatingfor wea hat is self-adjusting in response to tightening of the singlenut 46.

Another advantageous feature of the invention has to do with the factthat because of the intense,

heat of the exhaust gases, it is difficult to properly lubricate thepivotal connection, and because of; the lack of lubrication the wear dueto friction is greater than would be the case if it were lubricated. Bythe present construction I have greatly reduced the wear due to frictionand lack of 'lubri-. cation, and provided a novel construction forcompensating for the minimum of wear that does occur.

The bushings 42 also are efifective for spacing the side walls 26 withrespect to the mounting iug i8, and thereby properly positioning theclos ure flap 2G with respect to, the ring it and the exhaust pipe.

The wide area contact surfaces 36 and also provide an effective stopmeans for limiting the opening movement of the closure flap, and becauseof such wide area surfaces there is no impairment of any of the elementssuch as would be the case if certain elements contacted together inareas having sharp edges or limited areas of contact. It is pointed outthat the stop means provided by the surfaces 3% and 32 is, in contrast,an improvement over previous kinds in which the side walls 28 engage thering it] in which case the areas of engagement would be substantiallynot greater than point Contact, and consequent damage would result tothe ring, with possible breakage thereof.

It is also contemplated, in the present invention that instead ofproviding a brass bushing 34, the

entire ring it and lug l8, can be made of brass, or similar material, sothat the hardened steel pin 38 fitted in the aperture would engage thebrass surface thereof with the same effect as with the provision of thebrass bushing in the present construction.

The construction embodied in, the present in: vention results in unusualstrength and durability and enables longer wear of the device than wouldmounted on said supporting member, said closure member having anextension with spaced wall,

portions on opposite sides of said lug, said lug and Wall portionshaving aligned apertures therethrough, the apertures in said wallportions being threaded, a pin in the aperture in said lug and extendingthrough the apertures in said Wall portions, and bushings surroundingthe ends of said pin and threaded in the apertures in said wall portionswith their inner ends adjustably disposed in close relation to theadjacent surfaces of said lug for spacing said lug with respect to saidwall portions.

2. In combination, a supporting member having a mounting lug, said lughaving an aperture therethrough, a bushing of non-ferrous materialmounted in said aperture, a closure flap pivotally mounted on saidsupporting member, said closure flap having spaced wall portions onopposite sides of said lug, said wall portions having threaded aperturestherethrough in alignment with the aperture in said lug, a hardenedsteel pin in the aperture in said lug and adapted to rock therein, theends of said pin extending through the apertures in said wall portions,and bushings surrounding the ends of said pin and threaded in theapertures in said Wall portions, with their inner ends adjustablydisposed in close relation to the adjacent surfaces of said lug forspacing said lug with respect to said Wall portions.

3. In combination, a supporting member having a mounting lug, said lughaving an aperture therethrough, a bushing of non-ferrous material,press-fitted in said aperture, a closure flap pivotally mounted on saidsupporting member, said closure flap having spaced wall portions onopposite sides of said lug, said wall portions having threaded aperturestherethrough in alignment with the aperture in said lug, a hardenedsteel pin rockably mounted in said bushing, the ends of said steel pinextending through the apertures in said wall portions, bushingssurrounding the ends of said pin and threaded in the apertures in saidwall portions, with their inner ends adjustably disposed with respect tothe adjacent ends of said bushing in the lug for spacing said lug withrespect to said wall portions, and means fixedly securing said pin withrespect to said Wall portions so that said pin rocks in said firstbushing in response to pivotal swinging of said closure flap.

4-. In a device of the character disclosed, a supporting member adaptedfor mounting on the end of an exhaust pipe, said supporting memberhaving a laterally disposed lug, said lug having an aperturetherethrough, a closure flap adapted to close the end of the exhaustpipe, said closure flap having a laterally extending counterweight witha cavity therein, said cavity having spaced side Walls, said lug beingdisposed in said cavity, said side walls having threaded apertures inalignment with the aperture in said lug, a pin in the aperture in saidlug, the ends of said pin extending through the apertures in said sideWalls, exteriorly threaded bushings surrounding the ends of said pin andthreaded in the apertures in said side walls, said bushings beingadjustable into close relation to the adjacent surfaces of said lug, andmeans for looking said bushings in adjusted positions.

5. In a closure device of the character described, comprising a frameelement adapted to surround the terminal portion of an exhaust pipe,

a lug carried by and extending laterally from said 7 frame element, anda closure flap pivotally connected to said lug and adapted to normallycover the open end of exhaust pipe and movable to an open position bythe pressure of the exhaust gases discharging through said pipe, saidfiap having a laterally extending counter-weight for counterbalancing aportion of the overhanging Weight of said flap, said counter-weig11thaving a cavity formed in its underside between a pair of laterallyspaced apart walls, said flap being mounted on the frame with said lugprojecting into said cavity, between said Walls; the improvementwhereinsaid pivotal connection comprises a non-ferrous bushingpress-fitted in an aperture in said lug, a hardened steel pin rockablymounted in said bushing, one end of said pin having a bolt head and theother end being threaded, said pin extending through a ertures in saidwalls, the apertures in said spaced apart walls being threaded, secondbushings surrounding the ends of said pin and threaded in the aperturesin said walls, said second bushings being adjustable into engagementwith said non-ferrous bushing, said bolt head being engageable with theend of one of said second bushings, and a lock nut threaded on thethreaded end of said pin and engageable with the end of the other ofsaid second bushings.

6. In a closure device of the character described, comprising a frameelement adapted to surround the terminal portion of an exhaust pipe, 2.lug carried by and extending laterally from said frame element, and aclosure flap having an extension pivotally connected to said lug andadapted to normally cover the open end of the exhaust pipe and movableto an open position by the pressure of the exhaust gases dischargingthrough said pipe, said lug and extension having interengageable contactareas forming stop means for limiting the movement of said flap to openposition, said contact areas extending in one direction substantiallythe full transverse dimension of said lug and extending a substantiallyequal extent in a direction transverse thereto.

'7. In a closure device of the character described, comprising a frameelement adapted to surround the terminal portion of an exhaust pipe,

- a lug carried by and extending laterally from said frame element, anda closure flap pivotally connected to said lug and adapted to normallycover the open end of the exhaust pipe and movable to an open positionby the pressure of the exhaust gases discharging through said pipe, saidflap having a laterally extending counter-weight for counter-balancing aportion of the overhanging weight of said flap, said counter-Weighthaving a cavity formed in its underside, said flap being mounted on theframe with said lug projecting into said cavity, said lug and one wallof said cavity having interengageable contact areas forming stop meansfor limiting the movement of said flap to open position, said contactareas ex tending in one direction substantially the full transversedimension of said lug and extending a substantially equal extent in adirection transverse thereto.

CLINE HARRY HARMON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 140,303 Pritchard June 24, 1873 2,048,943 Munn July 28, 19362,421,838 Harmon et a1 June 10, 1947 2,482,390 Webber Sept. 20, 1949

